CVE-2021-31769 in X Smart
Summary
by MITRE • 06/21/2021
MyQ Server in MyQ X Smart before 8.2 allows remote code execution by unprivileged users because administrative session data can be read in the %PROGRAMFILES%\MyQ\PHP\Sessions directory. The "Select server file" feature is only intended for administrators but actually does not require authorization. An attacker can inject arbitrary OS commands (such as commands to create new .php files) via the Task Scheduler component.
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Analysis
by VulDB Data Team • 06/24/2021
The vulnerability identified as CVE-2021-31769 represents a critical security flaw in the MyQ X Smart system's MyQ Server component prior to version 8.2. This issue stems from improper access control mechanisms that allow unprivileged users to gain elevated privileges through manipulation of administrative session data. The vulnerability exists within the Windows-based system where administrative session information is stored in the %PROGRAMFILES%\MyQ\PHP\Sessions directory, creating an attack surface that bypasses intended authorization controls.
The technical exploitation of this vulnerability occurs through the "Select server file" feature which is designed exclusively for administrative users but fails to implement proper authentication checks. This misconfiguration allows any remote attacker to access administrative session data and subsequently manipulate the system through the Task Scheduler component. The flaw enables command injection attacks where malicious actors can execute arbitrary operating system commands, including the creation of new php files that can serve as backdoors or additional attack vectors. This represents a classic case of insufficient authorization controls leading to privilege escalation and remote code execution.
The operational impact of this vulnerability is severe as it fundamentally undermines the security model of the MyQ X Smart system. An unauthenticated attacker can leverage this flaw to execute commands with administrative privileges, potentially leading to complete system compromise. The ability to create new php files through the Task Scheduler component creates persistent attack vectors that could remain undetected for extended periods. This vulnerability affects not only the local system but also potentially exposes network infrastructure to further attacks, as the compromised system could serve as a pivot point for lateral movement within network environments.
Security professionals should note that this vulnerability aligns with CWE-284 (Improper Access Control) and represents a significant deviation from the principle of least privilege. The ATT&CK framework categorizes this as privilege escalation through access token manipulation and command execution. Organizations should implement immediate mitigations including updating to MyQ X Smart version 8.2 or later, restricting access to the affected session directory, and monitoring for unauthorized file creation activities. Network segmentation and firewall rules should be configured to limit access to the MyQ system components, while regular security audits should verify proper implementation of access controls and authentication mechanisms to prevent similar vulnerabilities in other system components.